Flash Mental Calc

Boost your mental math skills with Flash Mental Calculation! A simple and effective training app where numbers flash on screen and you calculate the sum as fast as you can. 【Features】 · Addition, Subtraction & Mixed mode · Customizable difficulty (digits, count, speed) · Sound & haptic feedback · Japanese / English / Chinese 【Premium - one-time】 · Mixed mode (addition + subtraction) · Unlimited custom difficulty · Accuracy charts & statistics